Process of extracting wool fat.



No. 680,963, Patented Aug. 20, [901.

F. W. ROBINSON, Decd. H. F. CUTTER, Executrix. PROCESS UF EXTBACTING WOOL FAT. (Application filed Mar. 26, 1898. Renewed Feb. 2, 1901.\ (No Model.

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No. 680,963. Patenfed Aug. 20, l90l. F. W. RUBINSUN, Decd.

. H. F. CUTTER. Executrix.

PROCESS 0F EXTRACTING WOOL FAT.

(Application filed Mar. 26, 1898. Renewed Feb. 2, 1901.)

(No Model.)

2 Sheets-Sheet 2 RRXS PETERS co. momnuo" wnsnmmou n lJNliTlED Erarns Parent Critics,

HARRIET F. CUTTER, OF EAST LYME, CONNECTICUT, EXECUTRIX OF FREDERICK XV. ROBINSON, DECEASED.

PROCESS OF EXTRACTING WOOL FAT.

SPECIFICATION forming part of Letters Patent No. 680,963, dated August 20, 1901. Application filed March '26, 1898. Renewed February 2, 1901. Serial No. 45,748- (No specimens.)

To all whom it may concern.-

Be it known that FREDERICK W. ROBINSON, deceased, who was in his life a citizen of the United States of America, and a resident of East Lyme, in the county of New London and State of Connecticut, and of Whose estate the subscriber, HARRIET F. CUTTER, a citizen of the United States, and a resident of East Lyme, is sole executrix, invented certain new and useful Improvements in Processes for the Recovery of Natural Grease from Wool, of which the following is a description, reference being had to the accompanying drawings, wherein- Figure 1 is a plan view, somewhat in the nature oi adiagram,of an apparatus designed for the practice of said improvement,with the upper portion of the wool-tank represented as broken away in order to show parts contained within said tank. Fig. 2 is an elevation in partial vertical section on the plane denoted by the broken line .90 m of Fig. 1. Fig. 3 is an end view of the wool-tank and certain pipe connections.

The objects of the improvement are the removal of natural grease from wool by the use of naphtha and dry steam, the complete removal of the naphtha from the Wool, and the saving of both grease and the naphtha.

In the accompanying drawings the letter a denotes the woo1-tankthat is, a tank for containing the wool under treatment. The top is closed by a cover 12, adapted to be secured air-tight to the tank. The wool in bales, bags, or fleece is introduced into the wool tank through its open top when the cover is off, which cover is then secured in place and the joint hermetically sealed. The wool rests on a finely-perforated table 19, overlying that part of the steam-pipes iwhich is within the wool-tank. Now all the air is exhausted from the wool-tank so far as is practical by ordinary means. For this purpose it is desirable to use a Kortin g exhauster cl, having between that exhauster and the wool-tank the condenser e and suitable piping. The exhaustion just spoken of is accomplished through pipe f, all other openings into the Wo0l-tank being meanwhile closed. A practical vacuum being thus established in the wool-tank, the valve f appurtenant to -air is admitted to the wool-tank through valve g, whereupon by gravity the liquid naphtha flows back into naphtha-tank No.1. This operation of giving the wool a naphthabath is repeated until the grease which was in the wool naturally is nearly all taken up.

by the naphtha. Generally three or four baths are requisite for this purpose; tically in administering these naphtha-baths to the wool the naphtha is taken alternately from tank No. 1 and tank No. 2, and. when the naphtha returns from the wool-tank practically unsoiled it is a sign that the grease in the wool has been nearly all taken up by the naphtha. Now the connection to said naphtha-tanks is closed, the connection to the con denser e is opened, this time the lower connection through pipe h, and a vacuum is es tablished in the condenser by means of the Korting exhauster, the effect of which is to draw over into the condenser all naphtha,

liquid or vaporous, which was in the wooltank, except a certain percentage which remains in the wool and which it is not possible to remove by this particular step of the process. From the condenser the naphtha is run back in liquid form into naphtha-tank No. 3. Now with a practical vacuum existing in the wool-tank the connection therefrom to the condenser is closed and the Wool is flooded and bathed with clean naph thasay from naphtha-tank No. 4. Now steam is let into the coil of pipes c' through pipe in. This coil surrounds the sides of the wool-tank and is also extended underneath the wool within the tank. The steam is used for this purpose at a temperature sufficient to boil the naphtha. At the same time that the steam is thus let on to boil the naphtha connection is made through pipe Z from the wool-tank to the condenser, wherein at this time the vacuum is maintained-this for the purpose of drawing off the naphtha-vapor from the Wool-tank in quantity sufficient to keep the pressure of the naphtha-vapor from increasing in the wooltank to a dangerous degree. This bathing operation being finished the liquid naphtha Prac-- is drawn off from the condenser into naphthatank No. 3. Now with the hot steam continued in the coil i the wool-tank is subjected to vacuum action alternately at the top and bottom through pipes l and h, which has the effect of removing from the wool the naphtha still contained therein. At the close of this operation the naphtha is run off from the condenser into naptha-tank No. 3. Now with the wool tank under vacuum dry steam, made so by separators m, which are of such construction as to remove practically all the moisture from the steam and whose pressure is kept down to five pounds, which can be effected by the reducing-valves 0, is admitted suddenly through pipe n into the wool-tank and then shut 01f. This pulsating steam-bath is repeated three or four times, and the effect is to remove every trace of naphtha in any shape from the wool, including the odor, and to transfer it to the condenser, where it is run into naphtha-tank No. 3. It is preferred to employ pulsations of steam for the following reasons: WVool is easily injured in its texture by heat, of which it is a poor conductor, and especially is this a fact if the heat is applied for a period of time to the wool when closely packed in atank. However, in order to thoroughly remove the naphtha from the wool the heat must be conveyed to each particle thereof, and as this can be done at short intervals only, as above described, pulsations become necessary and advantageous. Moreover, steam rushes into a vacuum atthe rate of fifteenhundred and fifty feet per second,while into the air its velocity is only six hundred and fifty feet, and hence when pulsations of dry steam are admitted, as above described, they almost instantaneously charge the entire volume of wool within the tank and can be Withdrawn before any appreciable or substantial injury thereto has been efiected. Now with the hot steam continuedin the coils 'L the wool-tank is subjected to vacuum ac tion alternately at top and bottom through pipes l and h, which has the edect of removing all moisture from the wool, which is absolutely necessary when wool is treated in the bale. Now the vacuum is shut ofi from the condenser. Air is admitted to the tank. The cover of this tank is taken off and the wool is removed clean, dry, and free from all odor of naphtha. The grease and the naphtha are in the naphtha-tanks and are separated and recovered in Well-known ways.

Now for a few words concerning the rationale of this process. If it were possible to obtain a perfect vacuum, then it would probably be possible to positively remove all the vapor of naphtha which might be in the wooltank simply by means of such a perfect vacuum; but such perfection of vacuum is not possible, for as the air or other gas becomes greatly rarefied as the process of exhaustion goes on the pump-valves finally cease to Work and leave traces of the rarefied air or gas behind. The only practical Way of improving on such a vacuum is by displacement, which can be effected by the agency of air, carbonic-acid gas, or dry steam at a low temperature. After the removal of such vapor has proceeded as far as it is possible by means of an ordinary vacuum process, then if the vacuum be broken by the admission of air the light vapor is displaced by the air and one cannot recover the naphtha-vapor from the air without the use of a gasometer, and there is danger of an explosion in doing this with a mixture of air and naphtha-vapor. The suggested displacement may be brought about by the use of carbonic-acid gas or any other inert gas; but this also necessitates the use of a gasometer to recover the uaphtha-vapor,in which there is a like danger of explosion.

The naphtha-vapor can be removed and recovered by the use of a small amount of dry steam at a low temperature. Three (3) pounds of pressure gives 222 Fahrenheit. Steam at a temperature of 212 Fahrenheit will enter a vacuum at the rate of seventeen hundred and fifty feet per second, while air at 34 Fahrenheit will enter at the rate of nine hundred and fifty-two feet per second. Were there no resistance in the path-such, for instance,as that offered by a bale of wool the steam would pass with the same velocity into a second vacuum-chamber; but the presence of a supposed bale of wool in its path would be to a. degree to retard the speed of this flow. With the wool (charged to an extent with naphtha-vapor in a vacuum-chamber) cold, then upon the admission of steam it would instantly condense upon the wool fibers, causing the wool to compact into a soggy mass, thus preventing the passage of the steam through it and making it impossible to dry the wool. As a cubic inch of wa ter weighing two hundred and fifty one grains, or about one-half an once, will, make seventeen hundred and twelve cubic inches of steam-say practically one cubic foot-it follows that if a cubic foot of steam were thus admitted to such a vacuum-chamber containing one pound of cold wool the actual condensation of all this steam distributed on the fibers of this pound of wool would be but.

one-half of an ounce of moisture, an amount not practically perceptible. Foreign wool contains about seventeen per cent. of moisture, or approximately two and one half ounces to a pound of wool. It will require four and one-half cubic feet of steam to condense two and one-half ounces of water upon one pound of wool. Taking a bale of wool weighing four hundred pounds it will require eighteen hundred cubic feet of steam to de posit seventeen per cent. of moisture thereon. High German authority gives it out that 240 Fahrenheit of heat does not injure wool subjected to such heat not more than three (3) hours and that the length of time to which wool is submitted to heat is more liable to do injury to the wool than the degree of heat.

By the application of wet steam to cold wool the condensation of moisture thereon is liable to cause the wool to become compacted together, which would necessitate a greater pressure of steam (higher heat) to remove naphtha-vapor therefrom. By the application of dry steam to Warm Wool in a vacuum little deposition of moisture is caused and naptha-vapor is rapidly removed, leaving the Wool (comparatively) dry and in no way inj ured by the temperature to which it has been subjected for the short time necessary to removeall trace of the naphtha-vapor.

The chemical and physical characteristics of spirituous distillation from petroleum are but indifferently understood by many, perhaps all, who have attempted the cleaning of wool by hydrocarbon. Distillate with a gravity of from 65 to 70 is termet naphtha. That over 70 is termed gasolene. A distillate of 00 gravity contains seventy parts of oleaginous properties and thirty parts of spirituous, while gasolene above 80 will vaporize in an atmospheric temperature of 70 Fahrenheit. At 10 above zero gasolene of 95 gravity will volatilize and is easily converted into gas. By using benzin of 60 it will readily be seen that it would require an exceedingly high temperature to completely volatilize all of it, as it is composed of seventy per cent. of oleaginous properties, so that there is certain to remain on the wool fiber an amount of oleaginous matter requiring a large amount of soap in the water to remove it. The recovery of this benzin in distilling from the grease or fat is impossible without scorching the fat. Nature has provided a protection for wool in this respect by enveloping it with moisture from five to seventeen per cent. in amount. This moisture may be said to be inherent in the wool, for if it be removed by heat and the wool then exposed to the air it will again take this moisture back to itself. It follows as a consequence that any process which robs the wool of this moisture (as by the use of hot dry air) is certain to make the wool brittle. WVhen such a process is practiced, it is necessary to use a high grade of gasolene, so as to be able to convert it into a gas which can be removed by air. The use of this spirituous product completely robs the wool of its moisture and being in a gaseous form acts still more powerfully in removing all moisture. The disadvantages of any process which compels the use of so high a grade of solvent must be very great, as the conversion of all this gas into a liquid form is impossible.

What is claimed as the invention is 1. The process of treating wool for the removal of grease and naphtha which consists in subjecting the wool in a tank under heat to vacuum action applied successively or alternately at dilierent points and then admitting pulsations of dry steam to drive out the naphtha, all substantially as described and for the purposes set forth.

2. The process of treating Wool which consists in removing the natural grease in large part by baths of naphtha; then boiling the wool in naphthain a vacuum; then subjecting the wool to vacuum action applied successively or alternately at different points and then under heat and in a vacuum subjecting the wool to comparatively dry steam, allsubstantially as described and for the purposes set forth. I p I I HARRIET F. GUTTEE, Emecutria: of Frederick l V. Robinson, dc

ceased. \Vitnesses:

DANIEL CALKINS, ABBIE A. OAULKINs. 

